If you have lost some of your master course lessons, or if you will be traveling you may request to send one or more lessons by email. For example, if you will be away for 5 days you can enter 216 at the beginning of a series and 220 at the end of a series and you will receive lessons 216, 217, 218, 219, 220 sent to you immediately, each lesson in a separate email. For a single lesson, just enter the same number in both places.